Add the button to the menubar, which is in the section defined with “theme_advanced_buttons…”
For my example, I will need to append “mycustombutton,” to it

You will then need edit the ui.css file with the wider button. For simplicity, add it to the end of the ui.css file so you can easily copy it when a new version of Tiny MCE is released. Replace the boldface “mycustombutton” with the name of your button. If you button name is mrfancypants, then it will be .defaultSkin a.mce_mrfancypants

That should be it! I plan on adding a lot more TinyMCE tutorials since I’ve decided to change the WYSIWYG component on all my applications to TinyMCE. CSS works really well with TinyMCE and cross platform browsers.